Support language bar swich for InputMethodSubtype

Change-Id: Ie49f0c1c7aea135331dc1d4a635197b3f4a96e93

1 files changed, 226 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/deprecated/languageswitcher/LanguageSwitcher.java b/java/src/com/android/inputmethod/deprecated/languageswitcher/LanguageSwitcher.java
new file mode 100644
index 000000000..639b7cdd0
--- /dev/null
+++ b/java/src/com/android/inputmethod/deprecated/languageswitcher/LanguageSwitcher.java
@@ -0,0 +1,226 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.android.inputmethod.deprecated.languageswitcher;
+
+import com.android.inputmethod.compat.InputMethodSubtypeCompatWrapper;
+import com.android.inputmethod.latin.LatinIME;
+import com.android.inputmethod.latin.Settings;
+import com.android.inputmethod.latin.SharedPreferencesCompat;
+
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.Editor;
+import android.content.res.Configuration;
+import android.text.TextUtils;
+
+import java.util.ArrayList;
+import java.util.Locale;
+
+/**
+ * Keeps track of list of selected input languages and the current
+ * input language that the user has selected.
+ */
+public class LanguageSwitcher {
+
+    private static final String KEYBOARD_MODE = "keyboard";
+
+    private final ArrayList<Locale> mLocales = new ArrayList<Locale>();
+    private final LatinIME mIme;
+    private String[] mSelectedLanguageArray;
+    private String   mSelectedLanguages;
+    private int      mCurrentIndex = 0;
+    private String   mDefaultInputLanguage;
+    private Locale   mDefaultInputLocale;
+    private Locale   mSystemLocale;
+
+    public LanguageSwitcher(LatinIME ime) {
+        mIme = ime;
+    }
+
+    public int getLocaleCount() {
+        return mLocales.size();
+    }
+
+    public void onConfigurationChanged(Configuration conf, SharedPreferences prefs) {
+        final Locale newLocale = conf.locale;
+        if (!getSystemLocale().toString().equals(newLocale.toString())) {
+            loadLocales(prefs, newLocale);
+        }
+    }
+
+    /**
+     * Loads the currently selected input languages from shared preferences.
+     * @param sp shared preference for getting the current input language and enabled languages
+     * @param systemLocale the current system locale, stored for changing the current input language
+     * based on the system current system locale.
+     * @return whether there was any change
+     */
+    public boolean loadLocales(SharedPreferences sp, Locale systemLocale) {
+        if (systemLocale != null) {
+            setSystemLocale(systemLocale);
+        }
+        String selectedLanguages = sp.getString(Settings.PREF_SELECTED_LANGUAGES, null);
+        String currentLanguage   = sp.getString(Settings.PREF_INPUT_LANGUAGE, null);
+        if (selectedLanguages == null || selectedLanguages.length() < 1) {
+            loadDefaults();
+            if (mLocales.size() == 0) {
+                return false;
+            }
+            mLocales.clear();
+            return true;
+        }
+        if (selectedLanguages.equals(mSelectedLanguages)) {
+            return false;
+        }
+        mSelectedLanguageArray = selectedLanguages.split(",");
+        mSelectedLanguages = selectedLanguages; // Cache it for comparison later
+        constructLocales();
+        mCurrentIndex = 0;
+        if (currentLanguage != null) {
+            // Find the index
+            mCurrentIndex = 0;
+            for (int i = 0; i < mLocales.size(); i++) {
+                if (mSelectedLanguageArray[i].equals(currentLanguage)) {
+                    mCurrentIndex = i;
+                    break;
+                }
+            }
+            // If we didn't find the index, use the first one
+        }
+        return true;
+    }
+
+    private void loadDefaults() {
+        mDefaultInputLocale = mIme.getResources().getConfiguration().locale;
+        String country = mDefaultInputLocale.getCountry();
+        mDefaultInputLanguage = mDefaultInputLocale.getLanguage() +
+                (TextUtils.isEmpty(country) ? "" : "_" + country);
+    }
+
+    private void constructLocales() {
+        mLocales.clear();
+        for (final String lang : mSelectedLanguageArray) {
+            final Locale locale = new Locale(lang.substring(0, 2),
+                    lang.length() > 4 ? lang.substring(3, 5) : "");
+            mLocales.add(locale);
+        }
+    }
+
+    /**
+     * Returns the currently selected input language code, or the display language code if
+     * no specific locale was selected for input.
+     */
+    public String getInputLanguage() {
+        if (getLocaleCount() == 0) return mDefaultInputLanguage;
+
+        return mSelectedLanguageArray[mCurrentIndex];
+    }
+    
+    /**
+     * Returns the list of enabled language codes.
+     */
+    public String[] getEnabledLanguages() {
+        return mSelectedLanguageArray;
+    }
+
+    /**
+     * Returns the currently selected input locale, or the display locale if no specific
+     * locale was selected for input.
+     * @return
+     */
+    public Locale getInputLocale() {
+        if (getLocaleCount() == 0) return mDefaultInputLocale;
+
+        return mLocales.get(mCurrentIndex);
+    }
+
+    private int nextLocaleIndex() {
+        final int size = mLocales.size();
+        return (mCurrentIndex + 1) % size;
+    }
+
+    private int prevLocaleIndex() {
+        final int size = mLocales.size();
+        return (mCurrentIndex - 1 + size) % size;
+    }
+
+    /**
+     * Returns the next input locale in the list. Wraps around to the beginning of the
+     * list if we're at the end of the list.
+     * @return
+     */
+    public Locale getNextInputLocale() {
+        if (getLocaleCount() == 0) return mDefaultInputLocale;
+        return mLocales.get(nextLocaleIndex());
+    }
+
+    /**
+     * Sets the system locale (display UI) used for comparing with the input language.
+     * @param locale the locale of the system
+     */
+    private void setSystemLocale(Locale locale) {
+        mSystemLocale = locale;
+    }
+
+    /**
+     * Returns the system locale.
+     * @return the system locale
+     */
+    private Locale getSystemLocale() {
+        return mSystemLocale;
+    }
+
+    /**
+     * Returns the previous input locale in the list. Wraps around to the end of the
+     * list if we're at the beginning of the list.
+     * @return
+     */
+    public Locale getPrevInputLocale() {
+        if (getLocaleCount() == 0) return mDefaultInputLocale;
+        return mLocales.get(prevLocaleIndex());
+    }
+
+    public void reset() {
+        mCurrentIndex = 0;
+    }
+
+    public void next() {
+        mCurrentIndex = nextLocaleIndex();
+    }
+
+    public void prev() {
+        mCurrentIndex = prevLocaleIndex();
+    }
+
+    public void setLocale(String localeStr) {
+        final int N = mLocales.size();
+        for (int i = 0; i < N; ++i) {
+            if (mLocales.get(i).toString().equals(localeStr)) {
+                mCurrentIndex = i;
+            }
+        }
+    }
+
+    public void persist(SharedPreferences prefs) {
+        Editor editor = prefs.edit();
+        editor.putString(Settings.PREF_INPUT_LANGUAGE, getInputLanguage());
+        SharedPreferencesCompat.apply(editor);
+        // When the current language is changed, the event for this change should be handled
+        // internally as a subtype switching.
+        mIme.notifyOnCurrentInputMethodSubtypeChanged(new InputMethodSubtypeCompatWrapper(
+                0, 0, getInputLocale().toString(), KEYBOARD_MODE, ""));
+    }
+}